Botany MP Pansy Wong has been cleared of any serious misuse of her Parliamentary travel allowance.

Parliamentary Service's investigation into the use of the so called travel perk by Mrs Wong and her husband Sammy has found "no evidence of systemic abuse" of the travel allowance by either.

Mrs Wong resigned from her Women's Affairs and ethnic affairs portfolios last month when it was revealed that she and her husband Sammy had done business while using the taxpayer-funded travel discount in China.

Under the rules of use, the discount - 90 per cent for Mrs and Mr Wong - is on airfares for private travel only and not to be used for business - though MPs are now allowed to use it for travel-related to their parliamentary work.

"The investigation, conducted for the Parliamentary Service by former senior public servant Hugh McPhail, looked into 13 international trips made by Pansy Wong and her husband together or separately since 2000.

"It found that one trip, a flight from Beijing to Lianyungang, China in December 2008, could have been in breach of the Speaker's Directions," Speaker Lockwood Smith said in a statement.

"While this trip was unplanned and inadvertent, it could be construed as having been for a private business purpose."

The report recommended Mrs Wong and her husband repay the travel rebate for that trip of $237.06 each."

Otherwise, the report found no evidence the couple had not complied with the Speaker's Directions regarding private international travel, Dr Smith said.

The report also examined the Wongs' use of the domestic air travel entitlement and their use of an electorate office at 735 Chapel Road, Botany, Auckland, as a registered office for a commercial business purpose. It found no evidence of non compliance with the rules around either.

"I am satisfied that the report thoroughly examined these matters. I now expect Pansy and Sammy Wong to repay the travel rebate for one trip as recommended in the report," Dr Smith said.

In a statement, Mrs Wong said she accepted the report's findings. She apologised, and said she and Sammy would refund the amount identified in the report.

She said she hoped to return to Cabinet but understood "that it has to be earned".

"My energy and focus now will be used to serve the people of Botany and promoting the interests of ethnic communities across our country. I am looking forward to returning to Parliament."

Mrs Wong said the experience of the last three weeks was not something she wanted to repeat and she was grateful for the support of her family, friends, supporters and colleagues.

She said she was grateful to Prime Minister John Key for allowing her the "time and space to go through the inquiry process in order to be able to give a factual and comprehensive account of my use of the travel rebate over the past decade".

Labour MP Pete Hodgson started the scrutiny on Mrs Wong's travel when he questioned her in Parliament as to whether she should have signed her occupation as a Government Minister, instead of Member of Parliament, when witnessing a business deal of her husband's in China.