The nightclub dancer at the centre of the sex trial of Silvio Berlusconi, the former Italian prime minister, has told a court that guests at the media tycoon's "bunga bunga" parties dressed as nuns, nurses and US President Barack Obama.

Morrocan-born Karima El Mahroug, better known by her stage name Ruby the Heartstealer, spoke on Friday as a witness in a trial at which several people are accused of inducing and aiding prostitution.

They include Lele Mora, a scout; Emilio Fede, a television anchor; and Nicole Minetti, a regional councillor and former showgirl.

Minetti was once Berlusconi's dental hygienist who graduated to a career in showbusiness and politics.

El Mahroug denied ever having sexual relations with Berlusconi, 76, and said she did not see him engaged in physical contact with other women at the parties.

Berlusconi is being tried separately for paying for sex with El Mahroug when she was a minor and then abusing office by having her freed from police custody after her arrest for theft.

Embarrassing appearance

El Mahroug's appearance is nevertheless an embarrassment for Berlusconi and a reminder of the legal threats that the billionaire businessman - who leads the centre-right and is a key partner in the governing coalition - faces.

A verdict in the sex trial is expected in June, and a conviction for tax fraud is moving to a final appeal.

Berlusconi says he has never paid for sex, denies any wrongdoing and says judges are politically motivated against him.

El Mahroug failed to appear as a witness at Berlusconi's trial in December because she was on holiday in Mexico.

In her Friday testimony, she challenged Berlusconi's assertion that events at his villa were elegant dinner parties.

Marysthelle Polanco, a glamour model and one of 14 women who became notorious after they were discovered to be housed at a Milan address at Berlusconi's expense, dressed up as Obama and Brazilian footballer Ronaldinho, according to El Mahroug.

On one occasion Minetti "dressed up as a nun ... and as she danced, she took off her clothes and was left in her underwear", El Mahroug told the court.

Cash in envelopes

Wearing a large grey scarf and her hair tied back in a sleek ponytail, she entered the Milan courtroom flanked by police, walking quickly past waiting journalists.

It was the first time she has testified about the parties.

El Mahroug said she received envelopes containing thousands of euros in cash from Berlusconi.

She said she spent the night at Berlusconi's villa on one occasion, after which she and several other women who had slept there shared breakfast with him.

El Mahroug was 17 when she attended the parties at the villa outside Milan.

She said she lied about her age and that she had told guests she was a relative of Hosni Mubarak, Egypt's former president.

Berlusconi's defence against the abuse of office charge is that he acted under the belief that El Mahroug was related to Mubarak, and that he needed to free her from police custody to prevent a diplomatic upset.

Source: Agencies