A modern Greek tragedy of incest, prostitution and violence continued, on Sunday, the theme of sexual and moral perversion which has emerged at this year's Venice Film Festival.

The audience flinched during 'Miss Violence', as traditional family relationships were shown to be hideously corrupted after one of the children commits suicide on her 11th birthday.

Films about necrophilia, child prostitution and domestic violence are among 20 new works vying for the coveted Golden Lion award at the 70th annual festival on the leafy Venice Lido.

"We decided not to deal with the economic crisis but rather to confront the crisis of values," the director of 'Miss Violence', Alexandros Avranas, told a news conference after the screening.

Festival director Antonio Barbera has said the line-up of films in the competition, which will be judged by a panel headed by veteran film maker Bernardo Bertolucci, shows a dark and violent reality.

Themis Panou, who plays the tyrannical father in 'Miss Violence', said he had to draw on Greek tragedy to help him play a character who was unlike anyone he had ever known.

"I think many men thought of sleeping with their mothers. Oedipus is not a chance event, and this is how I built my character," Panou said.

Sordid sex and violence infuse family relationships in Philip Groening's 'The Police Officer's Wife' and David Gordon Green's 'Joe', which also premiered at the festival.

The character of Wade in 'Joe', who shamelessly exploits his son and daughter for money, is "a man whose moral bankruptcy knows no limits," critic David Rooney said in trade paper the Hollywood Reporter.

Lester Ballard in James Franco's 'Child of God', on the other hand, is driven so far out of his mind and society that he seeks solace in necrophilia, and is even portrayed with sympathy.

The grisly sex scene is played "with a measure of real tenderness, which serves only to render the overall tableau all the more ghastly," critic Justin Chang said in trade publication Variety.

HINTS AT HORROR

In 'Miss Violence' the shock of the 11-year-old's suicide initially contrasts with the bland expressions on her family's faces and the stock images of a birthday party - paper hats and luridly iced cake - in a nondescript apartment.

Early hints at minor violence and psychological bullying foreshadow later scenes of depravity, at a similarly slow pace to the gradual spread of bruises over the body of domestic violence victim Christine in 'The Police Officer's Wife'.

German director Groening's film shows few scenes of violence in its detailed examination of the family's life, painstakingly split into 59 chapters, leaving the viewer to imagine exactly how Christine got her bruises.

"This is one reason why maybe some audiences may feel a little distressed at the moment when they feel they have to decide for themselves," Groening said after the screening.

Avranas said 'Miss Violence' could have been set anywhere, and Reni Pittaki, whose character is dumbly complicit in child prostitution for much of the film, likened the role to one from classical theatre, which tries to reveal universal realities.

"I saw in this woman the archetype of a tragedy, of a drama, of a Greek tragedy," Pittaki said.

Among films still to debut at the Venice festival before it ends on Sept. 7, are 'The Zero Theorem', a potential comeback for cult hero Terry Gilliam, and "The Unknown Known', a documentary about ex-U.S. defense secretary Donald Rumsfeld.