Lynda Spence, 28, has not been seen since April 13, when she left her parents' house in Glasgow Harbour.

She sent a text to her mother the next day stating that she had travelled to London, but her parents reported her missing a few weeks later.

Strathclyde Police said that the four men, aged 45, 41, 40 and 31, were detained last night before being charged.

A police spokeswoman said: "Four men were arrested and charged with the abduction and murder (of) Lynda Spence. They will all appear at Kilmarnock Sheriff Court today."

Ms Spence, who is also known as Lynda Zefaj, Lynda Palmer and Lynda Reilly, ran a business, Fraser Developments, which mainly arranged mortgages.

But not long before she went missing, the company experienced difficulties when several deals fell through.

It is understood she owes tens of thousands of pounds.

Police have been investigating sightings of her car in North Ayrshire and Argyll in late April and early May.

On June 2 this year a member of the public found an old mobile phone belonging to Ms Spence in a bin outside a shop in Kilbirnie, North Ayrshire.

It is believed the phone was put in the bin between 11am and 1pm on that day.

On Friday detectives searched a house in West Kilbride, Ayrshire, as part of their investigation into her disappearance.