The number of sexual offences against children recorded by Kent Police shot up by a almost 70% over a two-year period.

According to figures released by the NSPCC, 802 child sex abuse reports were received between 2012 and 2013, which rose to 1,356 the following year.

Last year, the charity received 122 calls to its helpline that were so serious, they were immediately referred to the police or children's services.

The charity says it is not clear why the number of reported offences has risen so significantly, but it could be attributed to greater awareness which is giving victims the courage to come forward.

However, there are also fears these figures represent the tip of the iceberg in terms of how many abused children are still suffering in silence.

NSPCC chief executive Peter Wanless said: "These figures are disturbing and clearly illustrate child sexual abuse is a continuing and widespread problem that needs urgent action.

"But we know this is still only a fraction of the true number of victims because some endure an agonising wait of many years before telling anyone – and others never reveal what has happened to them.

"It's time to throw down the gauntlet to government which has to ensure all sexual abuse victims get specialist treatment to help them recover.

"These figures are disturbing and clearly illustrate child sexual abuse is a continuing and widespread problem..." - Peter Wanless, NSPCC

"By the end of this current Parliament there should be no children living in the shadow of abuse."

But police say the spike is due to a "change of culture", as well as improvements to recording crime and the impact of the Jimmy Savile scandal.

A Kent Police spokesman said: "There continues to be an impact on crime figures after Kent Police set about a change of culture and a new and improved recording process following an inspection by Her Majesty's Inspectorate of Constabulary in 2013.

"This includes a particular focus on violent crime and sexual offences, which is reflected in the increase of reported offences between 2012/13 and 2013/14.

"In addition to improved crime recording, we continue to experience a slight increase in the number of historic sexual offences being reported as a result of increased confidence in reporting offences and media awareness following high profile investigations such as Operation Yewtree."

The spokesman added: "Kent Police takes all reports of sexual offences against children seriously no matter when the offence took place."

The NSPCC figures are revealed today as the charity launches its third annual report - How Safe Are Our Children? - at the charity’s annual conference in London.

The report compiles the most up-to-date child protection data that exists across the country.