SEARCHERS looking for missing woman Mary Yap have now deployed a high frequency underwater sonar unit which can cover 10 miles of river a day.

Police believe the 72-year-old mum-of-four, who went missing from Malvern on November 18, was last seen on Powick bridge over the River Teme.

The day after she went missing, a handbag believed to be Mrs Yap’s was found in the river.

Private search and rescue firm Specialist Group International (SGI) agreed to provide free aid to police and fire crews over two days earlier this month, after being approached by Mrs Yap’s family.

Six divers, working in shifts of two, began searching the river at 9.30am until the evening over both days.

SGI then returned on Thursday (December 14) to undertake another 48-hour search of the river – this time with the special device, which costs around £22,300.

“The last time we searched the river we didn’t have the sonar, because ours had broken, and we had to order one in from America,” said SGI chief executive Peter Faulding.

“We were purely diving then, which means we can only cover 200 or 300 metres a day, whereas the sonar can scan 200 metres in 20 minutes. It’s a brilliant piece of kit.”

He said the teams performed a “low level fly over the river to see if anything has snagged on the surface” on Thursday, before the main search began on Friday morning.

Mr Faulding, who first began using sonar equipment for forensic searches in 1995, said he was contacted by Mrs Yap’s son, and agreed to get involved in the search for free.

“He contacted me directly and asked could I help? I really felt for his situation and he is such a nice man. We want to find his mum for Christmas for him. We want the family to have that closure they need.”

He said: “They offered to pay but we said no. All the family are doing is covering our hotel bills. We will help out if we can. We are putting ourselves out there, we will give it all day.”