Relatives have positively identified three bodies found in a well as those of two Australian surfers and one American who went missing last weekend, Mexican authorities said on Sunday.

Baja California state prosecutors said the relatives had viewed the corpses recovered from a remote well about 15 metres deep and recognised them as their loved ones.

Thieves apparently killed the three, who were on a surfing trip to Mexico’s Baja peninsula, to steal their truck because they wanted the tyres. They then allegedly got rid of the bodies by dumping them in a well near the coast.

The well was located some four miles from where the foreigners were killed and also contained a fourth corpse that had been there much longer.

Three suspects are being held in connection with the case, which locals said was solved far more quickly than the disappearances of thousands of Mexicans.

Chief state prosecutor Maria Elena Andrade Ramirez described what likely would have been moments of terror that ended the trip for brothers Jake and Callum Robinson from Australia and American Jack Carter Rhoad.

She theorised the killers drove by and saw the foreigners’ pickup truck and tents and wanted to steal their tyres. But “when (the foreigners) came up and caught them, surely, they resisted”.

She said that was when the killers would have shot the tourists.

The thieves then allegedly went to what she called “a site that is extremely hard to get to” and allegedly dumped the bodies into a well they apparently were familiar with.

She said investigators were not ruling out the possibility the same suspects also dumped the first, earlier body in the well as part of previous crimes.

The thieves allegedly covered the well with boards.

“It was almost impossible to find it,” Ms Andrade Ramirez said, and it took two hours to winch the bodies out of the well.

The site where the bodies were discovered near the township of Santo Tomas was near the remote seaside area where the missing men’s tents and truck were found on Thursday along the coast.

Baja California prosecutors had said they were questioning three people in the killings, two of them because they were caught with methamphetamines. Prosecutors said the two were being held pending drug charges but continue to be suspects in the killings.

A third man was arrested on charges of a crime equivalent to kidnapping, but that was before the bodies were found. It was unclear if he might face more charges.

The third suspect was believed to have directly participated in the killings.

In keeping with Mexican law, prosecutors identified him by his first name, Jesus Gerardo, alias “el Kekas”, a slang word that means “quesadillas”, or cheese tortillas. Ms Andrade Ramirez said he had a criminal record and that more people may have been involved.