Lidia Thorpe has been forced to resign as deputy leader of The Greens.

It comes after the Senator failed to disclose her relationship with former bikie boss Dean Martin last year.

She was serving on the federal parliament’s law enforcement committee, which receives confidential briefings about organised crime.

Greens leader Adam Bandt says Thorpe showed a “significant lack of judgement” by failing to disclose her relationship with a former president of an outlaw motorcycle gang.

“I accept that I have made mistakes and have not exercised good judgement,” Senator Thorpe said in a statement.