An Immigration Department report on the 457 foreign worker scheme in Australia has found only rare instances of clear abuse.
Earlier this year Immigration Minister Brendan O'Connor announced a crackdown on visas, alleging rorting of the scheme.
Ever since, the Opposition and industry groups have been demanding he produce evidence to back up the claim.
Mr O'Connor at the weekend claimed that nearly one in 10,457 visas were being used illegitimately.
However, the report provided to the minister late last year found little evidence that employers discriminated in favour of overseas workers.
Opposition immigration spokesman Scott Morrison told the ABC the report does not support the minister's claims.