The senior detective leading the Madeleine McCann investigation is facing calls to step down after a woman jailed for the murder of her daughter claimed that his officers tortured her into confessing.

Leonor Cipriano, 36, told for the first time how she was forced to kneel on glass ashtrays with a bag over her head as police repeatedly hit her during almost 48 hours of nonstop questioning.

She is now serving a 16-year sentence for the murder of her eight-year-old daughter Joana, even though the body has never been found and she has since retracted her statement.

Chief Inspector Goncalo Amaral, who is jointly leading the Madeleine case, is to face a criminal hearing for allegedly concealing evidence that three of his colleagues tortured Cipriano. The hearing could be as early as next month.

Joana Cipriano disappeared from her home in Figuera, near Portimao on the Algarve, in September 2004, not far from where four-year-old Madeleine disappeared in Praia da Luz 143 days ago. Leonor Cipriano was arrested at 8am on October 14 and confessed after almost 48 hours of continuous questioning.

She retracted her statement a day later when she had access to a lawyer but was still charged and convicted of murdering her daughter.

Speaking from Odemira prison in west Portugal, she told a relative: “The police put a bag on my head, but I didn’t see what I was hit with. It was something like a baton. They made me kneel on two glass ashtrays and then they hit me. I couldn’t see who hit me because of the bag.

“It’s not true I fell down the stairs – the police hit me. I said it [the confession] because they beat me.”

A friend saw Cipriano shortly after the alleged attack. She said: “Her head was swollen, while she had huge bruises under the breasts, on the thighs and the legs.”

Amaral is accused of concealing evidence supporting allegations that three of his colleagues tortured Cipriano. The four detectives and a fifth, who is accused of fabricating evidence, deny the allegations and say Cipriano was injured when she threw herself down a flight of stairs.

Roy Ramm, a former Scotland Yard commander, said: “It is extraordinary that a man accused of an unresolved, serious complaint like this is still handling a high-profile inquiry. You would expect him at best to be in a desk job.”

Carlos Garcia, vice-president of the trade union for Portuguese police, which is defending Amaral and his colleagues, said: “They utterly reject the allegations.”

Cipriano’s boyfriend Leandro Silva, 41, a car mechanic, claims that he, too, was beaten when he was taken in for questioning in Faro in October 2004. “One officer grabbed me from behind, spun me round, then hit me in the stomach with a closed fist,” he said. “They also hit me from behind with a phone book. When they questioned me, a senior officer said, ‘You ate Joana’s body’. I couldn’t believe it. Then he said, ‘You cooked her and you ate her’. I thought they must be crazy – it was like something out of a horror movie.”

Silva is considering making a formal complaint.

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