An Australian journalist has suceeded in a daring underwater rescue of his Laotian girlfriend by swimming with scuba gear under the Mekong River to Laos and bringing her back to Thailand.

The journalist, John Everingham, 28, was the last Western correspondent in Laos before being expelled 10 months ago. He was forced to leave behind his girlfriend, Keo Sirisomphone, 25.

Everingham said he exchanged coded letters and messages with Keo to set up rendezvous points, but his first two attempts to swim under the river were foiled by Laotian patrols.

On Saturday Everingham made a third attempt. The fast-running river was swollen by heavy rains and he said he could see Keo on the far bank a mile away, where she was waiting with a fishing pole and a child to avoid suspicion.

Battling currents and tossed by whirlpools, he crawled along the muddy bottom using a compass to guide him. It took two attempts.

"I crawled out on the bank," he said. "She was walking away . . . I yelled . . . Then she saw me and started running forward. She fell into my arms."

Fearful of being seen by dozens of armed soldiers sitting along the river bank, Everingham put a life vest on her and one of his two breathing regulators in her mouth and plunged back into the river. Keo cannot swim. With their faces just at the surface of the water and a quick release strap binding them together, they crossed to Thailand.