Firstly, you need to determine what kind of property it is.

If it's a landed property then before paying any monies (earnest deposit), always get a copy of the issue document of title which you can then proceed to conduct a land search at the relevant land authority. either you make a copy of the seller's NRIC or you write down the number and name, these particulars on the NRIC must correspond with the details reflected on the land search.

If it's a stratafied property still under master title then same thing as above but instead, request for a copy of the Sale and Purchase Agreement and the Deed of Assignment however this may not be absolute prove because the seller may still possess a copy of these documents if the sale has in fact been terminated previously. You need to get the particulars of the Developer from the Sale and Purchase Agreement and then call them up to confirm if the parcel is in fact belongs to the person represented to you as the owner.

The safest method is to always deposit any monies with a solicitor's firm because they are duty bound as stakeholders and you need to instruct them not to release until a status of the property is verified and confirmed. if the solicitor acted not as instructed, you can at least sue them to recover the monies. If the seller refuses for such arrangements and demanded that monies be paid to him directly and immediate, something is fishy.

No one genuine seller is as desperate as that.

They'll probably threatened you that he/she has 100 people interested in the property and he is on the way to meet up with them after this or some bullshit stories like that.

Whatever it is, it's a property and you are buying. Always take your time to shop and don't rush into things.