A young humpback whale that kept becoming stranded on a beach in eastern China has been found dead after a third rescue attempt failed. The death was probably caused by diseases which damaged its health and navigation system, Xu Xinrong, a whale expert from Nanjing Normal University told Modern Times . The whale, which weighed three tonnes, was estimated to be between three and five years old. The species usually live for 50 years. Experts told the newspaper that it probably lived 200km away but had been unable to find its way back because of the damage to its navigation system. The whale was also found to have thinner blubber than its healthy peers. Stranded humpback whale rescued in China The seven-metre-long animal was first spotted on a beach in Qidong city in Jiangsu province on Monday. It was guided back to the ocean with the help of a fishing boat after a five-hour rescue effort by local police. But the following day the whale became stranded again on the same beach. The rescuers waited until 5.40pm when the tide began to rise and dug a tunnel to help it get into the sea. The whale was seen heading out into the ocean about 7pm, the report said. Huge whale found dead on Chinese beach may have choked on fishing net Despite efforts by police and fisherman who set up patrols to stop the whale becoming stranded again it returned to the area for a third time. On that occasion rescue attempts proved futile and the whale died about noon on Wednesday. Police said the animal would be used as a specimen for scientific study.