Apple has bought a driverless car start-up in a sign that its long-running but secretive self-driving vehicle plans remain active.

The tech company has bought Drive.ai, a company founded by former Stanford University students, that had been developing self-driving software.

Apple is believed to be bringing several of the start-up’s engineers on board, although notices filed in California suggest a significant number of staff will be laid off.

Drive.ai had been conducting trials of its technology in Texas, and was known for its bright orange vans with exterior screens that communicated to pedestrians what the vehicle was doing.

It had raised around $77m (£61m) but was believed to be looking for a buyer, and Apple is likely to have purchased it for significantly less than that.

Local media in San Francisco had reported that Drive.ai was shutting down after it told California state officials that it would be permanently closing and laying off 90 employees.

Apple has pursued cars and self-driving software for years but its plans have shifted multiple times with little sign that the company is close to showing the technology to the public. At one time, it is believed the company was developing its own car under the codename Project Titan. The plan was supposedly scrapped, with chief executive Tim Cook later saying that Apple was working on “autonomous systems”.

"We sort of see it as the mother of all AI projects. "It’s probably one of the most difficult AI projects actually to work on,” he said in 2017.

The division has been through multiple rounds of layoffs in recent years as its priorities have shifted. Earlier this year, it hired Tesla’s head of electric powertrains Michael Schwekutsch and last year re-hired Doug Field, who had worked at Apple before joining Tesla as its chief vehicle engineer.

An Apple spokesman confirmed the deal but did not say how much it had paid.