Greater Manchester Police are reported to have apologised to a gay man who was forced to give a DNA sample for a national database under new powers for investigating 'historical' crimes.

The 50-year-old former soldier said the sample was taken because of a conviction 30 years ago for having consensual sex with another man, despite the fact the law under which he was convicted no longer applies.

The incident is one of a number of instances where police have been accused of demanding DNA from gay people convicted of offences decades ago under legislation which has been abandoned. They are part of Operation Nutmeg, being carried out by forces across the country following the introduction of the Crime and Security Act, which became law last year.

Figures published by the BBC under the Freedom of Information Act show that 653 people were charged in 2012 for alleged offences carried out on social media sites – out of a total of 4,908 offences reported to 29 forces in England, Scotland and Wales. That compares with figures of 46 out of 556 in 2008.

The revelations come in the wake of publication by the Director of Public Prosecutions Keir Starmer QC (pictured) of interim guidelines setting out the approach prosecutors should take in cases involving communications sent via social media. The guidelines are designed to give clear advice to prosecutors and ensure a consistency of approach across the CPS to these types of cases.

Mr Starmer said: "These interim guidelines are intended to strike the right balance between freedom of expression and the need to uphold the criminal law. They make a clear distinction between communications which amount to credible threats of violence, a targeted campaign of harassment against an individual or which breach court orders on the one hand; and other communications sent by social media, such as those that are grossly offensive, on the other.

The Sentencing Council for England and Wales is consulting on proposals for how guidance for courts on sexual offences should be brought up to date. It aims to give more focus to the impact on victims and reflect advances in technology, while making sure offenders are dealt with effectively.

Its draft sentencing guideline, which covers offences such as rape, child sex offences, indecent images of children, trafficking and voyeurism, proposes a variety of changes to how offending is dealt with by the courts.

The council believes that as well as physical harm, the psychological and longer term effects on the victim should be more fully reflected. Factors such as stalking and previous abuse, including violence, can make the victim more vulnerable to harm and are set out as factors that can be taken into account.

On 14 November more than 1,300 officers from the Metropolitan Police targeted what were described as "key figures in organised criminal networks, gang members and street-level offenders", as part of the Met's 'total war' on crime. Operation Stimtone 2 was the largest day of action the force has ever put together to tackle criminals specifically by investigating their financial activities.

There were been 175 arrests for a variety of offences, including money laundering, fraud, theft and handling stolen goods. Police had seized around £348,000 under the Proceeds of Crime Act (POCA), including an Audi.

According to a statement from the Met: "Drug dealing, trafficking and prostitution, money laundering, rogue landlords, vehicle documentation fraud, handling stolen goods, conspiracy to defraud charities, as well as seizing assets and confiscating money from criminals using the Proceeds of Crime Act 2002 are on Operation Stimtone 2's agenda."