Senator apologises after smear accusations

Liberal senator Ian Macdonald has been forced to apologise after linking Labor's Penny Wong to a controversial Chinese businessman.

As the chairman of a Senate hearing on Tuesday, he tried to shut down questions about Huang Xiangmo's links to the Liberal Party.

"You're not going to answer questions about Mr Wong," Senator Macdonald told department officials.

"Is it Wong, is it? Any relation to Senator Wong?" he added.

Labor senator Louise Pratt quickly weighed in.

"No, Huang, H-U-A-N-G," she said.

Labor committee members later accused him of trying to smear Senator Wong, just because the two surnames happened to be Chinese.

"It was a desperate attempt to distract from the line of questioning," Labor senator Kimberley Kitching said.

"You are smearing Senator Wong."

Senator Macdonald claimed it was a "throwaway line" and accused Labor senators of being "very sensitive" about the issue.

"If Senator Wong has taken offence then I apologise to her, but if she does take offence she has a very thin skin," he said.

Senator Macdonald is expected to lose his Queensland Senate seat at the upcoming federal election.

Later on Tuesday, Labor leader Bill Shorten issued a statement to Chinese language media calling out the senator's comment and seeking a full apology.

"It's disgraceful that a Liberal senator would suggest that people of Asian background all have the same name or are all related," Mr Shorten said.