Several years ago, a pal of mine dragged me to a meeting at an office near Raffles Place that could have been a game-changer - at least that's what the guys in suits told me.

It was a multi-level marketing presentation, as slick as the name suggests, with eager sales associates milling around, desperate to make me a bundle.

All very simple: I just had to put in about $1,300 and sell similar plans to my friends and relatives. My cash was supposed to be buying me some health products, but the plan was touted from start to finish as a money-spinning scheme.

I was tempted but being a bit low on savings at the time - just after my national service - meant I had to decline.

There were persistent phone calls for a few weeks after that - including from my friend who I realised had invested earlier - before they finally gave up.

Plenty of others were - and are - less reticent, which is why such alternative investments have become increasingly popular in recent years.

High inflation, low interest rates and pricey stocks and property mean the thrill is gone for more traditional investment classes.

There seems to be no limit to the imagination regarding the actual assets being touted. For those bullish on real estate, we have programmes that pool money from investors to buy land or property either locally or overseas.

Then there are schemes for gold trading, wine investment and even animal farms overseas.

These of course add to the multi-level marketing and timeshare schemes that have been here for years.

They tend to share two common factors - promises of handsome financial gains and charismatic leaders capable of convincing the most sceptical of investors that they will very likely make big money.

Several alternative investments may indeed be able to live up to their promises of generating cash for investors.

But I have grown very wary of such programmes and am glad I did not participate in the scheme being flogged to me those years back, even though there is a chance I could have made money from it.

I now go as far as to stay well clear of seminars if I know they will be used to promote alternative investments.

After all, the Consumers Association of Singapore last month raised the red flag over the high-pressure selling tactics of timeshare companies.

Alternative investments also often hit the headlines for the wrong reasons.

Recently, The Gold Guarantee's chief executive apparently disappeared, leaving investors in the gold trading company deeply concerned that they would lose all their money.

The warning signs for alternative investments are plain to see. For one thing, most schemes are not regulated by the Monetary Authority of Singapore (MAS), so there is little recourse for investors.

But the authority has warned the public to "exercise great care and vigilance" before committing themselves to such unregulated schemes.

The Commercial Affairs Department - Singapore's white-collar crimes unit - has the power to investigate if any fraud is uncovered. But by that time it is usually too late for investors to recover their money.

Programmes that invest overseas may be covered by laws in those countries - but these may not be well-established or understood by investors here.

This is unlike the more traditional investment classes.

A company's shares listed on the Singapore Exchange are subject to the Securities and Futures Act, which is administered by MAS. Breaching the Act attracts fines and even a jail term.

There is also a well-established legal framework to protect property buyers here.

For small-time investors, the stock market may offer a decent option. Valuations may have risen, but there are plenty of blue-chip companies with long operating histories that should provide some level of comfort.

Exchange-traded funds offer an even better alternative, allowing investors to buy into a portfolio of stocks so the impact is limited if one or two stocks collapse.

Of course, the market has its own dangers. Thousands of investors in so-called S-chips are in limbo after governance and accounting scandals at some of these China companies listed here.

At the end of the day, investors would do well to diversify their assets, since all investments come with risks.

They should also remember that investments that promise high rewards almost always come with high risks. This is an age-old nugget of wisdom followed by fund managers and investment experts all around the world. I will be very sceptical of any investment scheme which claims that this principle does not apply to it.