Two critical after head clash at Vic pool

A woman may have been trying to save her drowning boyfriend when she also got into trouble at a Melbourne pool, with both now fighting for life.

The woman was found fully clothed and floating facedown while her boyfriend, also an IT student from India, was lying at the bottom of the pool.

No one saw what happened but emergency services say the 23-year-old woman and 22-year-old man may have hit heads.

Victoria Police Senior Sergeant Justin Goldsmith said she may have jumped in to help him because she was still dressed, but it was unclear what happened.

"There has been a suggestion of a head clash," Sen Sgt Goldsmith said.

Both were unconscious when found at Greensborough's WaterMarc aquatic centre on Sunday evening.

Ambulance Victoria group manager Graeme Parker said the man sank to the bottom where he remained for a matter of minutes after suffering cardiac arrest.

The couple remain in a critical condition at the Austin Hospital.

Mr Parker praised the lifeguards at the packed leisure centre who applied CPR and gave the two "a chance for survival" before paramedics arrived.

He said the accident, combined with the drowning of a five-year-old boy at Lysterfield Lake on Sunday, served as a timely reminder for the community to exercise caution around water-based activities.