MOSCOW - Russian President Vladimir Putin signed a law on Wednesday banning the adoption of children by same-sex couples, as part of an increasingly conservative agenda the Kremlin is pursuing since his return to power.

Earlier this week Putin signed another law banning gay "propaganda", which human rights groups say has fuelled hate crimes against homosexuals.

Putin, who has embraced the Russian Orthodox Church as a moral authority and harnessed its influence as a source of political support, has championed socially conservative values since starting a new, six-year term in May 2012.

The latest law aims to protect children from "dictated non-traditional sexual behaviour" and rid them of "distresses of soul and stresses, which according to psychologists' research, are often experienced by children raised by same-sex parents," according to a fact sheet on the Kremlin's website.

The 60-year-old president denies there is discrimination against gays.

Homosexuality was decriminalised after the collapse of the Soviet Union in 1991, but a recent poll by the independent Levada Centre found 38 percent of Russians believe gay people need treatment and 13 percent said they should face prosecution.

Gay rights activist Nikolai Alexeyev said of the new law: "I think it will lead to an increase in corruption in the (adoption) process, but many foreigners, including homosexuals, will still be able to adopt Russian children in the future."

Foreign adoptions in Russia are largely run by agencies which act as go-betweens for state institutions and adopting families.