Families of passengers aboard Malaysia Airlines Flight MH370 on Sunday called on the Malaysian government to extend a search contract with deep-sea exploration company Ocean Infinity to continue the hunt for the missing aircraft.

The Boeing 777, carrying 227 passengers and 12 crew members, disappeared on March 8, 2014, while flying from Kuala Lumpur to Beijing, becoming one of aviation’s greatest unsolved mysteries.

Several search missions have been conducted in the southern Indian Ocean over the past decade, but none have successfully located the wreckage.

Last March, Malaysia agreed to allow Ocean Infinity to resume the search under a “no find, no fee” arrangement, meaning the company would receive $70 million only if the aircraft wreckage was discovered.

However, Malaysia’s Air Accident Investigation Bureau (AAIB) said on Sunday that the latest search operations had produced no results so far. Two search phases lasting 28 days covered about 7,571 square kilometres (2,923 square miles) of seabed.

The AAIB said operations were occasionally interrupted by poor weather and rough sea conditions, with the second phase ending on January 23.

“The government remains committed to keeping the families informed and will continue to provide updates when appropriate,” the bureau said.

Voice370, a group representing families of those on board, warned that Ocean Infinity was unlikely to resume the search before its current contract expires in June, due to the approaching winter season in the southern hemisphere and worsening sea conditions.

The group urged the Malaysian government to approve any request from Ocean Infinity to extend the agreement and to offer similar terms to other exploration companies interested in joining the search.

“A simple extension of the contract period, without changing the core terms of the agreement, would allow the search to continue without delay,” the group said.

Ocean Infinity previously conducted search operations for the aircraft but failed to locate significant wreckage.

In a 2018 report, Malaysian investigators were unable to determine what caused the aircraft to disappear, although they did not rule out the possibility that the plane may have been deliberately diverted from its original route.