Author Truman Capote, in an affidavit to support Claus von Bu low's appeal of two attempted-murder convictions, says Martha (Sunny) von Bu low drank heavily, used drugs and showed him how to use a hypodermic needle.

In a sworn statement to the Rhode Island Supreme Court, Capote maintained the now-comatose utilities heiress showed him how to inject himself at his New York City apartment in about 1954.

A year and two weeks ago, Claus von Bu low, 56, was convicted by a Newport, R.I., Superior Court jury of two attempts to murder his wife with injected insulin. Von Bu low, a one-time top aide to the late oil billionaire J. Paul Getty, maintained his wife's coma was the result of overindulgence in alcohol, drugs and sweets.

Capote's affidavit was submitted last week to the state's highest court. Von Bu low, a Danish-born financier, is free on $1 million bail while he appeals the convictions that could put him behind bars for 30 years.

In his statement, Capote wove a story about a woman who experimented with drugs, was obsessed with her weight and enjoyed alcohol. The alleged hypodermic show-and-tell was prompted by a conversation with Capote about Vitamin B-12 injections, the writer said.

"She took out the hypodermic needles and she rolled up her--this little jacket that she was wearing--she rolled up her sleeve and said, 'I usually just give this to myself in the hip,' " Capote said in the statement.

"She said, but with a little laugh, 'I think I'll teach you in the arm. It's just as easy, and once you learn it you can do it yourself,' " he continued.

Capote said the needle contained distilled water.

In 1979, he said, he met Sunny von Bu low by chance and she suggested they go to a hotel for drinks. He said they both consumed six Manhattans during a three-hour conversation.

He said Sunny von Bu low told him she had been injecting herself with a mixture of the pain killer Demerol and amphetamines for what she said was " 'the most relaxing, pleasurable experience you could have.' "

In separate affidavits filed last week, two New York doctors said they believed Sunny von Bu low was in an irreversible coma because she had tried to commit suicide.

Dr. Michael Baden, deputy chief medical examiner for Suffolk County, N.Y., said he believed neither the 1979 nor 1980 Christmas holiday coma Sunny von Bu low suffered at her Newport mansion was caused by improper insulin injections by her husband.

The first coma, he said, "was produced by innocent medical causes." The second a year later was an attempt at suicide, he said.

Dr. Leo A. Dal Cortivo, a Suffolk County toxicologist, also noted there were "no needle marks or tissue damage" found on Sunny von Bu low after she lapsed into her second coma. Author Truman Capote On the von Bulow Case

PROVIDENCE, R.I. (March 30)--Author Truman Capote, in an affidavit to support Claus von Bu low's appeal of two attempted-murder convictions, says Martha (Sunny) von Bu low drank heavily, used drugs and showed him how to use a hypodermic needle.

In a sworn statement to the Rhode Island Supreme Court, Capote maintained the now-comatose utilities heiress showed him how to inject himself at his New York City apartment in about 1954.

A year and two weeks ago, Claus von Bu low, 56, was convicted by a Newport, R.I., Superior Court jury of two attempts to murder his wife with injected insulin. Von Bu low, a one-time top aide to the late oil billionaire J. Paul Getty, maintained his wife's coma was the result of overindulgence in alcohol, drugs and sweets.

Capote's affidavit was submitted last week to the state's highest court. Von Bu low, a Danish-born financier, is free on $1 million bail while he appeals the convictions that could put him behind bars for 30 years.

In his statement, Capote wove a story about a woman who experimented with drugs, was obsessed with her weight and enjoyed alcohol. The alleged hypodermic show-and-tell was prompted by a conversation with Capote about Vitamin B-12 injections, the writer said.

"She took out the hypodermic needles and she rolled up her--this little jacket that she was wearing--she rolled up her sleeve and said, 'I usually just give this to myself in the hip,' " Capote said in the statement.

"She said, but with a little laugh, 'I think I'll teach you in the arm. It's just as easy, and once you learn it you can do it yourself,' " he continued.

Capote said the needle contained distilled water.

In 1979, he said, he met Sunny von Bu low by chance and she suggested they go to a hotel for drinks. He said they both consumed six Manhattans during a three-hour conversation.

He said Sunny von Bu low told him she had been injecting herself with a mixture of the pain killer Demerol and amphetamines for what she said was " 'the most relaxing, pleasurable experience you could have.' "

In separate affidavits filed last week, two New York doctors said they believed Sunny von Bu low was in an irreversible coma because she had tried to commit suicide.

Dr. Michael Baden, deputy chief medical examiner for Suffolk County, N.Y., said he believed neither the 1979 nor 1980 Christmas holiday coma Sunny von Bu low suffered at her Newport mansion was caused by improper insulin injections by her husband.

The first coma, he said, "was produced by innocent medical causes." The second a year later was an attempt at suicide, he said.

Dr. Leo A. Dal Cortivo, a Suffolk County toxicologist, also noted there were "no needle marks or tissue damage" found on Sunny von Bu low after she lapsed into her second coma.