An unidentified trainer works with a killer whale during the Believe show at SeaWorld in Orlando, Fla., in February 2010. (Richard Baum/Reuters)

SeaWorld Orlando in Orlando, Fla., has been fined $75,000 US by a federal job safety agency on Monday for three violations uncovered while investigating the February death of a trainer who was grabbed by a killer whale and dragged underwater.

The Occupational Safety and Health Administration categorized the most serious violation as "wilful," or showing indifference or intentional disregard for employee safety. That citation, carrying a $70,000 penalty, was for exposing workers to drowning hazards when interacting with killer whales.

The agency proposes not allowing trainers to have any physical contact with Tilikum, the killer whale responsible for Dawn Brancheau's death in February, unless protected by a physical barrier.

The OSHA report described Tilikum as having "known aggressive tendencies."

The six-ton whale was one of three orcas blamed for killing a trainer in 1991 after the woman lost her balance and fell in the pool at Sealand of the Pacific near Victoria. Tilikum also was also involved in a 1999 death when the body of a man who had sneaked by SeaWorld Orlando security was found draped over him.

SeaWorld trainers were forbidden from getting in the water with Tilikum because of the previous deaths. But the killer whale still managed to grab Brancheau's long hair as she lay on her stomach on a cement slab in eight centimetres of water. The cause of death was drowning and traumatic injuries.

The OSHA report also suggests that trainers not work with other killer whales at the park, either in the water or out of water, unless they are protected by a barrier, deck or oxygen-supply system underwater.

"SeaWorld trainers had an extensive history of unexpected and potentially dangerous incidents involving killer whales at its various facilities, including its location in Orlando," OSHA said in a statement released with the report.

The second citation, deemed serious, was for failing to install a stairway railing system beside the stage in Shamu Stadium. That citation carried a $5,000 penalty.

The third citation was considered "other-than-serious" and was for failing to have weather-protected electrical receptacles at the stadium. That citation didn't have a penalty.

SeaWorld spokesman Fred Jacobs said the park will contest the citation.

"SeaWorld disagrees with the unfounded allegations made by OSHA today," Jacobs said in a statement.

Meanwhile, a former director of health and safety at SeaWorld Orlando went public Monday with allegations that the theme park tried to obstruct the investigation by blocking OSHA investigators from coming to the property and refusing to give the agency some documents, charges SeaWorld denies.

Linda Simons, who was fired in April after only two months on the job, has filed a whistleblower lawsuit against SeaWorld with OSHA.

"SeaWorld did not want to co-operate at all," Simons said in a telephone interview. "They really felt that if the information was going to get out to the public, it would hurt their business."

SeaWorld co-operated fully with OSHA, said Jacobs, who accused Simons of threatening the theme park with negative publicity if she didn't get a payment from the company. Simons' attorney, Maurice Arcadier, said his client never tried to extort SeaWorld but was seeking reinstatement and back pay.