The Indian navy says none of its submarines surfaced in the area
Indian naval officials have denied media reports that Chinese warships forced an Indian submarine to surface in a stand-off in waters off Somalia.
Reports in China said that after the submarine was detected by sonar, it was pursued by two Chinese destroyers and an anti-submarine helicopter.
The Chinese ships had been on passage to take part in anti-piracy patrols.
The two sides were reportedly trying to test each other's sonar systems for weaknesses.
However, the Indian navy says none of its submarines was forced to surface in the area.
"None of our submarines surfaced in the Gulf of Aden region as reported in a section of the Chinese media," a naval official told Indian reporters.
Several Indian newspapers reported the allegations, and cited Indian naval sources as admitting their submarine had tracked the Chinese warships. "Every nation does it," one was quoted as saying.
Chinese submarines surprised the US navy in October 2006, by successfully tracking the USS Kitty Hawk in the Pacific Ocean.
Several versions of one report on the incident were circulating on Chinese websites this week, including Sina.com and QQ.
These claimed that a tense stand-off occurred between Chinese warships and an Indian submarine on 15 January near the Bab Al-Mandab Strait, which separates Yemen and Djibouti, at the western end of the Gulf of Aden.
The Chinese destroyers had picked up an unidentified submarine on their sonar, the reports said.
The Chinese navy soon identified it as a 70m-long (230ft) vessel armed with 20 torpedoes.
The Chinese reports said the Chinese ships had sent an anti-submarine helicopter to help track the submarine, which had tried to jam the Chinese warships' sonar system.
But the two destroyers eventually cornered the submarine and forced it to surface, reports said. The Indian vessel then apparently left without further confrontation.
Chinese media said the submarine had been trailing the Chinese ships since they had entered the Indian Ocean on the way to Somalia.
But India has denied the reports, which have also not been carried by China's official news outlets, Xinhua and the China Daily.
There were more than 100 pirate attacks in 2008 in the Gulf of Aden and Indian Ocean, in what is one of the world's busiest shipping lanes.
An EU anti-piracy task force set up in December was the first such naval operation of its kind. India, Iran, the US and China are among other nations with naval forces off Somalia.