A young Moldovan dancer has testified that she and the captain of the cruise liner Costa Concordia were lovers and was on the bridge when the ship capsized off the coast of Tuscany.
The dancer, Domnica Cemortan, testified at Tuesday's hearing in Grosseto where the captain faces up to 20 years in prison if convicted.
Some 32 people died when the boat hit a reef and partially sank in January.
The testimony may prompt prosecutors to query the quality of Cemortan's previous testimony, which had shown the captain in a more positive light.
Cemortan tried to dodge the question of whether she was romantically involved with Francesco Schettino who is married, and only responded positively after being told she risked criminal charges for refusing to reply.
She had previously described Schettino as a "hero" and said he deserved the gratitude for bringing the ship nearer to shore rather than letting it sink out at sea.
Captain Schettino is on trial for causing the shipwreck, abandoning ship and manslaughter after the cruise liner carrying 4000 people ran aground off Tuscany's Giglio island, killing 32 passengers.
Schettino has claimed he had to abandon the capsizing boat while people were still aboard before it became impossible to launch any more lifeboats, and he planned to direct the rest of the evacuation from shore.
Survivors have described a delayed and confused evacuation.
The 114,500-tonne ship, on a week-long Mediterranean cruise, speared a jagged granite reef when, prosecutors allege, Schettino steered the ship too close to Giglio's rocky shores as a favour to a crewman whose relatives live on the island.
The reef sliced a 70-metre-long (230-foot) gash in the hull. Seawater rushed in, causing the ship to rapidly lean to one side until it capsized, then drifted to a rocky stretch of seabed just outside the island's tiny port.
Schettino is the only person on trial after four crew members and an official of the ship operator Costa Cruises, a division of Carnival Corp, were sentenced to terms of up to 34 months in prison after pleading guilty last year.