Madonna is named as co-defendant in the Los Angeles case

Yael Oestreich, a former vice president with the company, is seeking compensation for loss of earnings as well as general damages.

She alleges she was refused a promised salary raise and became a target of "inappropriate sexual inquiries".

Madonna and Maverick co-founder Guy Oseary are listed as defendants in the case filed in Los Angeles.

Ms Oestreich alleges chief executive officer Mark Morgan fired her without reason last July and accuses him of sexual harassment.

'Failed to investigate'

Her complaint against Madonna and Mr Oseary is that they allegedly "failed to conduct a reasonable investigation into defendant Morgan's background before hiring him and knew or should have known of his propensity for sexual harassment and discrimination".

She alleges she was called "uptight" for not joining in conversations about sex and was not taken seriously when she complained of harassment.

Among future projects planned for Maverick Films is a dramatisation of the 1971 Stanford prison experiment.

Madonna is hoping her own acting career can be revived with Hello Suckers, a musical she is co-writing in which she will play a 1920s Vaudeville star.