A maths teacher presumed dead after vanishing in his light aircraft was under police investigation after two pupils said he offered them cash to pose for photos.

Amateur pilot Gerry Mepham's plane was last seen on Friday. Despite a massive search involving helicopters, lifeboats and divers, no trace of him or his plane has been found.

Before he set off he told a friend he would not be coming back.

The 55-year-old from Barnham, near Bognor, had been suspended from Priory School in Fratton, Portsmouth, following a serious allegation made against him by two female pupils.

Police investigated the allegations but no charges had been brought.

Mr Mepham took off from Goodwood airfield, near Chichester, on Friday and is thought to have headed out to sea.

RAF radar tapes show what is believed to be his Piper Tomahawk plane off the Sussex coast, in the Bognor area. It then vanishes from the screen.

A woman at Mr Mepham's home in Elm Grove said his disappearance was "very upsetting" and she did not want to talk further.

Mr Mepham has taught mathematics and IT at the secondary school, which has 1,300 pupils, since 1975.

Headteacher Brian Shimell said: "We are concerned over Gerry's disappearance and hope he is found safe and well."

Police spokesman PC Mark White said: "Sussex Police are still treating this as a missing person enquiry.

"However, as the aircraft is yet to be located, the Air Accident Investigation Unit has been advised and is attending to give professional advice to the ongoing search.

"The area which is being searched is clearly visible from the shore and so police are appealing for any witnesses that may have seen a light aircraft flying off Pagham Harbour between 3pm and 5pm on January 10."

Jo Osborne, of Portsmouth's local education authority, said: "I can confirm a serious allegation had been made against a teacher at Priory School and the teacher has been suspended while a full investigation is carried out."