Judging by the rhetoric politicians on both sides have been regurgitating this week, most asylum seekers who come by boat are turning up with no documents, burning their passports and/or refusing to help authorities identify them.

“People who have destroyed their papers, people who refuse to co-operate in getting access to papers will find themselves at the back of the processing queue,” said new Immigration Minister Tony Burke, in one of several press conferences about the topic.

It was a policy directive the Liberals were quick to point out had been theirs all along. Opposition immigration spokesperson Scott Morrison discussed it on ABC Radio National on Monday:

Kelly: Scott Morrison, what percentage of asylum seekers arriving by boat destroy their documents and papers?

Morrison: Well, we know that more than 90% who turn up don’t have any documents. The ultimate percentage of those that have been thrown away is not able to be determined at this point. But what we do know is that the vast majority of people, more than 90%, go through airports in either Jakarta or other ports within Indonesia or Malaysia. And whether those documents are false or whether those documents are genuine to get them on to that plane is an issue. But we do know that those documents aren’t there when people turn up in Australia.

Kelly: So 90% of the people arriving on the boats to Australia have no documentation?

Morrison: Not just no passports, I’ve got to stress, no documentation.

Except that “over 90%” claim — one that Ben Packham has also written in The Australian — doesn’t quite hold up.

First of all, the most recent in-depth data comes from a budget Estimates committee in May 2011, when the Department of Immigration answered a question by Liberal Senator Michaela Cash on the percentage of irregular maritime arrivals (the government jargon term for asylum seekers arriving by boat) landing in Australia without documentation in the last three financial years.

The department says the average number of IMAs arriving without official documentation between 2008-2011 was 81.21%. This is the most current data the department has on the situation, although Morrison’s office assures Crikey his “over 90%” figure came from Immigration (we asked to see the precise figures, but Morrison’s office didn’t return our emails or calls).

Part of the difficulty is there’s no clear-cut definition of exactly what the government uses to classify someone as “documented”. In practise it means an asylum seeker who can provide a verifiable official identity document that includes a biometric photo, with a passport being the preferred option. Other forms, such as a national identity card that includes a photo or a UNHCR card, may be valid, depending on the strength of the document and its country of origin.

Burke’s office tells Crikey that a birth certificate or driver’s license can be used as initial identifying documentation, while the Department of Immigration says that’s unlikely, although several documents together may help. Most asylum seekers arrive with birth certificates, drivers licences, school certificates, letters from local priests, photocopies of identity cards, etc, however they are officially classified as “undocumented” if they can’t produce reputable state-issued photo identification upon arrival. The other forms of ID are used to help identify them and process their claims at a later stage.

“People may not have passports, but there’s also very good reasons for that,” Ian Rintoul, an activist from the Refugee Action Coalition, told Crikey. People smugglers often create fake passports to allow asylum seekers to enter ports in Indonesia or Malaysia and then remove the passports from asylum seekers before they board boats to Australia, often so they can re-use the fake names and passports. Many people smugglers also often demand that asylum seekers give up their mobile phones and genuine passports before embarking on the boat voyage.

Asylum seekers do occasionally destroy their passports but there is no data on how many do this. Sometimes it’s because Indonesia and Australia are more likely to deport asylum seekers found with a valid travel document. “I would tell any asylum seeker to arrive here without their passport, because if they’ve got a valid passport it’s far easier for the government to deport them,” said Rintoul.

Plus, it depends where they come from. Feili Kurds are stateless and not issued identification by Iran, despite spending decades there; Tamils often struggle to get passports issued by Sri Lanka; Afghans coming via Pakistan may not have a passport, but often have Pakistani drivers licences and school certificates.

The closest Crikey can find to Morrison’s “over 90%” claim is when Senator Cash asked a supplementary budget Estimates hearing question on October 15 last year about how many IMAs flew in to Indonesia but then arrived by boat to Australia passport-less (therefore assuming they must have destroyed it in between). This data comes entirely from entry interviews with asylum seekers, meaning it only represents those IMAs that willingly admit they flew in to Indonesia. In 2011-2012, 87% (1673 people) of those that flew in to Indonesia arrived in Australia undocumented. Between June 30, 2012 and October 31, 2012 (the most recent time period available), 78% (1551 people) were undocumented.

Regardless, those numbers show only a small percentage of the total IMAs. In 2011, Australia received 4565 asylum seekers by boat, while 17,202 asylum seekers arrived by boat in 2012 (the Department of Immigration has calendar year figures while the Senate has financial year figures, just to make the whole thing more confusing).

Therefore we judge Morrison’s “over 90%” claim as mostly rubbish.

Want more recent data on how many asylum seekers are undocumented? According to the Department of Immigration, our best bet would be more questions asked at Estimates. Over to you, Senator Cash …