A top official in Kazakhstan has called claims that Israeli-made spyware was deployed to monitor top officials including the current president "without evidence", as multiple countries began probing the allegations.

Hungary, Israel and Algeria on Thursday joined France in announcing investigations into allegations that journalists, rights activists and 14 heads of state were spied on using software called Pegasus developed by Israel's NSO Group.

But the deputy head of Kazakhstan's presidential administration Dauren Abayev said media reports on the list of targets leaked to rights groups were no more than "rather intriguing information without any evidence" in the ex-Soviet state's first comments on the scandal.

"Realistically you can include anyone in this list, and thereby sow seeds of doubt in the country, among the elite, among journalists, and so on," Abayev said in an interview with the state broadcaster Khabar on Thursday.

The Israeli NSO Group's Pegasus software -- able to switch on a phone's camera or microphone and harvest its data -- is at the centre of a growing storm after a list of about 50,000 potential surveillance targets was leaked to rights groups.

Amnesty International and French media nonprofit Forbidden Stories collaborated with a clutch of media companies, including the Washington Post, the Guardian and Le Monde, to analyse and publish the list.

The widening scandal is drawing in countries from Saudi Arabia and the United Arab Emirates to Morocco, India and a host of other mostly emerging economies.

In Kazakhstan's case, reported targets of the software include Kassym-Jomart Tokayev, the current president, who was handpicked as a successor by the Central Asian country's founding leader Nursultan Nazarbayev.

Other individuals on the list include current Prime Minister Askar Mamin, the present mayor of Almaty city, Bakytzhan Sagintayev and the veteran civil activist Bakytzhan Toregozhina.

Mamin and Sagintayev have been key figures in Kazakhstan's power transition that began when Nazarbayev stepped down as head of state in 2019.

The 81-year-old has retained several influential positions including leadership of the ruling party Nur Otan and chairmanship of the security council.

Upon inauguration, Tokayev proposed renaming the capital Astana "Nur-Sultan" in Nazarbayev's honour -- a change that went into effect almost immediately.

Toregozhina, a long-time rights defender, wrote on Facebook Tuesday that she had "always known" that her communications were being tracked in a post that featured a winking emoticon.