AN Australian lawyer being detained in Mongolia may be caught up in a fight over returns from a Rio Tinto mining operation, the head of an Australian parliamentary delegation which visited the mine recently says.

Tony Windsor told AAP on Monday he had no knowledge of the case of Sarah Armstrong, who works for a Rio Tinto subsidiary.

“But I imagine it would be linked to arguments over returns from the mine,” he said.

“It”s not all that dissimilar to the (Australian) Mineral Resources Rent Tax.”

The delegation, members of the Regional Australia committee, went to Mongolia and Canada to see how other countries are dealing with controversial fly-in fly-out and drive-in drive-out mining workforces.

In Mongolia, it visited Rio Tinto”s giant Oyu Tolgoi copper mine in the first week of September.

Mr Windsor, who made a brief statement to parliament on Monday, said Rio would need a fly-in fly-out workforce, mainly from the capital, Ulaanbaatar, but also from China.

However, Rio was “prioritizing building the local workforce through building a local community”.