BP robots, controlled using advanced IT systems, have lowered a cap onto the gushing oil well in the Gulf of Mexico.

The robots, known as remote operating vehicles, are operated by technicians from vessels on the surface using a combination of manual and automated functions. The same robots are traditionally used to help effect standard repairs on wells.

The news comes as the company precision-monitors the drilling of a relief well next to the damaged well, using systems from technology supplier Vector Magnetics. This is a failsafe option being employed, as the new cap is not yet certain to stop all the oil and gas at such a depth.

Last night, US coastguard Admiral Thad Allen said the locating of the new cap marked “significant progress” on efforts to stop the spill. BP is now conducting extensive tests on the site, shutting off the valves to measure the pressure and gauge if any oil is escaping.

Three weeks ago, BP experienced a serious accident when one of the four-tonne robots crashed into the existing cap. The coastguard attributed the accident to the high number of ROVs, twelve, operating in close proximity to the well head. It is not known whether human error or technology faults, or a combination of both, caused the accident.

CIO 100 listed BP has spent $3.5 billion (£2.3 billion) on the clean-up efforts so far, and is also committed to funding a $20 billion relief fund for individuals and businesses affected by the spill. Numerous reports have speculated other companies, including Exxon-Mobil, may make an approach to buy BP assets, but no formal move has been made.

Meanwhile, as BP digs the two relief wells it is using Wellspot monitoring systems from supplier Vector Magnetics to precision-measure its efforts. The distance monitoring systems, known as ranging technology, are widely reported as being typically largely accurate, but the unusual depth makes the operation more difficult.

BP has so far drilled to a depth of nearly 18,000 feet parallel to the damaged well, and is set to drill horizontally as it attempts to intersect it. Each drilling movement is done in stages, measuring distance to the well using the Wellspot technology, watched by technicians on the surface.

The first relief well is due to be completed in about a month’s time. Heavy liquid will be pumped into it to slow the oil, and then it will be cemented shut.

Pressure continues to mount in the US to ascertain exactly what chain of events caused the spill, and a commission set up by President Barack Obama is holding its preliminary hearings.

Early investigations by BP are likely to be brought to the fore, after they revealed a host of IT systems, cementing and process errors appeared to contribute to the devastating explosion in April, which caused the spill.