The National Party is facing scrutiny from the Electoral Commission for not including the cost of an online video to promote its Asian candidates in its election expenses return.

NZ on Air is also investigating allegations that National MP and Mt Albert candidate Melissa Lee used staff hours funded by the taxpayer to film and produce the video clip through her production company, Asia Vision.

Two staff who work for Asia Vision helped make the "National Asian Team" clip on YouTube which is fronted by Pansy Wong and has footage of National's other Asian candidates. Asia Vision was given about $1.2 million last year by NZ on Air to produce Asia Down Under.

Ms Lee - presenter and producer on Asia Down Under for 13 years prior to becoming an MP - has denied any taxpayer-paid resources were used for the video clip.

Yesterday, Green Party co-leader Russel Norman complained to the Electoral Commission about National's failure to declare it in their expenses, saying while it appeared to be "pro bono" the costs of production should be declared.

In their election expense returns, parties and candidates must declare the commercial value of professional services used for election advertisements, whether or not the party actually paid for them.

National's general manager Mark Oldershaw said the two staff were volunteers and the labour of volunteers is not an election expense.

Ms Lee said the equipment used was owned by the production company and not paid for by NZ on Air. However, a former staff member told TV3 it had happened during work hours.

NZ on Air's chief executive Jane Wrightson said Ms Lee had assured her the two staff involved had done the filming voluntarily and in their own time. She said she had no reason not to believe her but had asked for Asia Down Under's film crew logs to be couriered to her to inspect. She said if she found any discrepancies she would "call in the auditors".

Ms Lee is also denying allegations she acted inappropriately by continuing to work on Asia Down Under while she was a candidate, saying she was not involved in any election stories.

Labour MPs yesterday accused Ms Lee of unethical behaviour and misuse of taxpayer funding. Labour leader Phil Goff said she had not disclosed she was a candidate when she applied for - and got - a further $1.2 million for Asia Down Under in September last year.

However, NZ on Air's Ms Wrightson rejected suggestions Ms Lee had not disclosed she was standing for Parliament.