Mourners Gather For Boris Nemtsov Funeral

Thousands of Russians have turned out to pay their respects to the Kremlin critic who was gunned down in a Moscow street.

Mourners queued from the early hours of Tuesday morning to file past the coffin of the opposition leader Boris Nemtsov, lying in state in central Moscow.

At one point the line of people stretched around half a mile long and hundreds had to be turned away.

The former deputy prime minister and long-time critic of Russian President Vladimir Putin was shot dead last Friday close to the Kremlin.

Gennady Gudkov, a prominent Kremlin opponent, said in a speech given next to the coffin: "The shots were fired not only at Nemtsov but at all of us, at democracy in Russia."

One mourner told Sky News' Moscow Correspondent Katie Stallard he was a "great politician" whose death was a "tragedy for Russia".

Mr Nemtsov was later buried at the Troekurovskoye cemetery on the outskirts of Moscow.

No suspects have been arrested following his murder, considered the most shocking political assassination of Mr Putin's rule.

Leading Russian opposition figures have suggested the murder was politically motivated, although authorities deny any involvement, saying it could have been a provocation aimed at tarnishing Mr Putin's image.

The chief witness to the killing, Mr Nemtsov's Ukrainian girlfriend Anna Duritskaya, who has now left Russia after claiming she was barred from leaving by investigators, has said she did not catch sight of the killers.

The Kremlin has pledged to hold a full investigation into what Russian foreign minister Sergey Lavrov has described as a "heinous crime".

Although one mourner told Sky's Katie Stallard she did not feel confident the killers would be brought to justice.

"Even if we have some results, I wouldn't be able to trust them," she said.

Several leading international figures are among the crowds of mourners, including former British prime minister Sir John Major and US ambassador John Tefft.

"If anyone believes that his (Nemtsov's) voice will be silenced by his murder, then I believe they have made a very serious error," the former prime minister told Sky News.

He called for a "thorough, comprehensive investigation" into the killing.

Meanwhile, a number of Polish and Latvian officials say they were barred from entering Russia to attend the funeral.

Poland's foreign ministry said Polish senate speaker Bogdan Borusewicz was refused entry in retaliation for European Union sanctions over Ukraine.

Latvian MEP Sandra Kalniete said she was not given a reasonable explanation for the ban, but told news agency AFP she thought her "clear and explicit" opposition to Russia's actions in Ukraine may have played a role.

According to colleagues, Mr Nemtsov had been working on a report which apparently included concrete evidence that Russia was directly involved in the separatist movement which erupted in Ukraine last year.

He had also spoken of his fear of assassination following the murders of a string of other prominent opposition figures since Mr Putin came to power 15 years ago.

On Sunday tens of thousands of protesters marched through the streets of central Moscow to honour his legacy. Opposition leaders said the protest was also aimed at stopping a "campaign of hate" directed at those who question Mr Putin's rule.

Many of the demonstrators carried portraits Mr Nemtsov, as well as placards declaring "I am not afraid" and "He died for Russia's future".