It’s sad but true that many people don't concentrate on making their Will until the last minute, and then when they do they make a sudden decision to benefit one person to the exclusion of the rest of the family. It may be a nurse or a carer, or one of the family, but whenever it happens there is potential for a bitter dispute.

The recent case of Barrett v Bem is a classic example.

Martin Lavin died in 2004. Now, seven years later and after going to the High Court, the Court of Appeal and back to the High Court again, his Will has been held to be valid, but only by the slimmest of margins, and after a great deal of expense.

Mr Lavin was a bachelor, and at the date of his death left seven surviving brothers and sisters. While in hospital and terminally ill he decided to make a new Will leaving everything to his eldest sister, Anne. This upset numerous other members of the family, who subsequently challenged the validity of the Will.

Mr Lavin died in hospital about three hours after he signed the Will (or, as will become apparent, did not sign it). He was very frail and clearly had great difficulty in writing at all, but his mind was still clear.

Arrangements had been made for two nurses to come and witness the Will which had been prepared for him, and Anne was also present at that meeting in the hospital.

The formalities required for "a testator" to make a valid Will are extraordinarily strict. This is necessary because if there should later be a dispute, the main witness will, by definition, have died.

For the purposes of this case, there were three main rules which were considered, which can be briefly summarised as follows (although the rules in full are much more complex):

1. A Will can be signed by a testator in the presence of two witnesses, when the testator and the witnesses all sign the Will while they are still in the room together (the usual procedure);

2. A Will can be signed for the testator and in his name by someone else in the presence of the testator “and by his direction”; the testator must intend this to give effect to his Will and “acknowledge” his signature; again two witnesses are required.

3. Nobody who witnesses a Will can take a benefit under it.

Everything turned on the precise chain of events in the hospital on the day of Mr Lavin's death, and the bitter dispute within the family led to a close examination of exactly what had happened.

The Will appeared to have been signed by Mr Lavin - his name was written there - but when handwriting experts were called in they found that the handwriting was too strong and he could not have written it himself; somebody else had written in Mr Lavin's name. There was a great deal of argument about whether someone had guided Mr Lavin's hand, or had signed on his behalf; and if they had, whether it was " by his direction".

There were allegations of forgery and a cloud of uncertainty which resulted in the Court at the first hearing deciding that the Will was invalid.

By the time of the third hearing much more information had come to light, both the nurses had been found and a great deal more detailed work had been done. Even then, nobody could remember exactly what had happened, and the evidence was conflicting. The judge decided that much of it could not be right.

However, as long as a Will is not a forgery or invalid for other reasons, the Courts fortunately do their best to uphold it if they believe that it represents what the testator actually wanted.

Ultimately, and mainly on the basis of the evidence of the handwriting expert, the judge decided that the Will was not a forgery, and that Anne herself had written in Mr Lavin's name at the end of the Will. He also decided that it had been signed by Anne on Mr Lavin's behalf, in his presence and by his direction intending to give effect to the Will, and it was consequently valid.

So in the end, the Will was upheld, but the next question was whether Anne should be disqualified from taking a benefit under the Will.

Although a witness to a Will cannot take any benefit under the Will, perhaps surprisingly there is no rule that disqualifies a person who signs on behalf of the testator, as Anne did. There was no suggestion she had acted improperly, so she was finally able to inherit the estate.

Sadly, however, by that time she herself had died, as had five of the other brothers and sisters, and in the end it was Anne’s daughter and grandchildren who eventually took what was left of the estate.

It is yet another object lesson of the greatly increased danger of challenge to Wills which are made at the very end of a person's life, and when there are likely to be aggrieved family members. In those circumstances it is worth taking immense trouble to ensure there is absolutely no doubt that all the formalities have been strictly followed.