Chinese spy ship Yuan Wang 5, known to be fitted with various tracking and surveillance devices, has entered the Indian Ocean Region, ahead of a plan by India for a likely test firing a long-range ballistic missile in the Bay of Bengal, people familiar with the development said on Tuesday.

It is learnt that the Indian Navy is keeping an eye on the movement of the Chinese ballistic missile and satellite tracking ship.

The docking of the ship at Hambantota port in August had triggered a diplomatic row between India and Sri Lanka.

Open source intelligence expert Damien Symon on Monday tweeted that "Yuan Wang 5, #China's missile and satellite tracking vessel has entered the #IndianOcean region." There is no official comment on the reports of the presence of the spy ship in the Indian Ocean Region.

As per laid down protocol, India recently issued a NOTAM (Notice to Airmen/Notice to Air Missions) about a missile test.

It is not clear whether India will go ahead with the plan for the missile test in view of the presence of the Chinese spy ship.

According to experts, the Chinese vessel was last spotted in the Sunda Strait of Indonesia.

The visit of the Chinese ship to the Indian Ocean comes amid increasing concerns over growing forays into the region by Chinese military and research vessels.

India is bolstering defence and security ties in the Indian Ocean with like-minded countries in the backdrop of concerns over China's growing forays into the region, considered the backyard of the Indian Navy.