Retirees have been warned once again about pension scams after a financial adviser found that one in five over-50s may have been targeted by fraudsters looking to trick them out of their savings.The survey, conducted by YouGov on behalf of Retirement Advantage (formerly MGM Advantage), found that 17% of over-50s and 20% of over-55s have been approached by a company offering to help them access their pension early.Most had been contacted by phone (50%), while a quarter (24%) were targeted by mail and a further 23% by email.The scammers promise their victims they can unlock a pension early by using some kind of legal loophole or a one-off investment opportunity.Andrew Tully, pensions technical director at Retirement Advantage, said: "It is clear that there are already scammers preying on people who might like the idea of using the new pension freedoms to take large amounts of cash from their pension schemes."The scammers may be offering 'get rich quick' schemes or even early access before age 55 to trick people out of their hard-earned savings. Retirees need to be on their guard: if an opportunity sounds too good to be true, it almost certainly is."Tully said the government and the financial services industry must work together to help protect consumers, adding that the government must be more proactive in seeking our criminals and prosecuting them.To help retirees feel equipped to deal with potential scammers Retirement Advantage is highlighting five key things to be alert for:1. An offer to help you access your pension savings before age 55. It is only possible to do this in rare situations, for instance if you are very ill, so be careful and always check with your pension provider.2. A recommendation to take a large amount of money, or your whole pension pot, in a lump sum and invest it. There are significant tax implications if you take lots of your savings in one go, so check the tax position before you make any decisions.3. Warnings that the deal is limited and you must act now. Choosing the right retirement income product(s) is a big decision and shouldn't be done quickly or under pressure.4. An encouragement not to get professional financial advice or talk to Pension Wise. An adviser would be able to explain the rules and tax implications of different options and help you make the best choices for your personal circumstances, so be very suspicious if this is discouraged.5. Contact by somebody who is not on the Financial Conduct Authority (FCA) Register. The Register is a public record of all the regulated firms and individuals in the financial services industry, including retirement income providers and investment companies.