Britain’s largest security firm has claimed it has been “vindicated” following an investigation into its work with Israel.

G4S said the results of an 18-month probe of its work with Israeli officials in the Palestinian territories had shown there was no “general failure” in its respect for Palestinians’ human rights.

A Organisation for Economic Co-operation and Development (OECD) ruling published on Tuesday cleared G4S of having had an adverse impact on the lives of Palestinians through its contracts with Israel.

The firm had been investigated following a complaint to the OECD from the British-based group Lawyers for Palestinian Human Rights.

A G4S spokesperson said: “The report does not find any general failure by the company to respect the human rights of the people on whose behalf the complaint is made, or any failure to respect human rights in regard to its own operations.

“It refers to breaches of the guidelines which the report acknowledges are for technical reasons.”

Debbie Walker, G4S communications director, said the company would “continue to work with customers and business partners to safeguard human rights and ethical standards in line with the UN guiding principles on business and human rights and in accordance with best practice”.

Shares in the company rose on Tuesday after it said the OECD findings would allow it to pitch for security contracts from other governments in the future.

But Lawyers for Palestinian Human Rights argued that the ruling had shown violations in relation to Palestinians’ human rights.

The charity added that there had been failings in issues relating to the installation and maintenance of security measures including baggage-scanning equipment and metal detectors used at checkpoints.

Tareq Shrourou, the charity’s director, said: “By reason of its business relationship with the Israeli state agencies who violate international law, G4S has been found in breach of its human rights obligations under the OECD guidelines.”